Eiden Northstar, a carefree young noble, realizes the harsh reality of his monarchical heritage, after the assassination of the Supreme Ruler of the Nesolian Empire.  Being badly injured, and knowing his family is lost in an unknown magical dimension are shocking enough. But, accidentally listening to his own uncle plotting against him?  Running away seems the best idea.  The long and perilous journey to reunite with his family and to save the dying magic of his world teaches Eiden about the unseen world beyond the luxuries of his Royal life.  **** The broken key is a high fantasy, classic hero's journey type of story.